Method and device for operating a winding device of a textile machine producing cross-wound bobbins

ABSTRACT

A method and device for producing cross-wound textile bobbins using a creel for holding a cross-wound bobbin, a bobbin drive roller operated by a single drive to rotate the bobbin and a thread traversing mechanism driven by a single motor. At a predetermined bobbin diameter or a predetermined thread length, a thread guide of the traversing mechanism is positioned to adjust a thread end reserve for an adjustable time span. While the thread end reserve ( 10 ) is being produced, a thread storage suction nozzle ( 60 ) particular to the winding head acts on the thread ( 7 ) running onto the bobbin ( 8 ) to intermediately store excess thread length being produced during the winding of the thread end reserve ( 10 ) and to insure a minimum thread tension to reliably fix the thread end reserve ( 10 ) on the bobbin body or the cross-wound bobbin tube.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of German patent application 10 2007 023 490.4, filed May 19, 2007, herein incorporated by reference.

BACKGROUND OF THE INVENTION

The invention relates to a method for operating a winding device of a textile machine producing cross-wound bobbins and a textile machine winding device for carrying out the method.

It has been conventional for a long time in conjunction with the production of cross-wound bobbins, to provide such winding bodies both with a thread start reserve and also with a so-called thread end reserve. The thread end reserve of the cross-wound bobbin is generally formed, in this case, in that after the completion of the bobbin body, some of the thread windings which have been wound crosswise are firstly unwound again from the bobbin body and then wound again as a parallel winding either onto the bobbin surface or onto the tip of the cross-wound bobbin tube.

Corresponding methods and devices for producing a thread end reserve of this type are known both in conjunction with open end spinning machines and also from automatic cross-winding machines in various embodiments and described in detail in numerous literature references.

A method is known for example from German Patent Publication DE 36 02 574 A1, in which a service unit which can be moved along the workstations of a textile machine producing cross-wound bobbins, after the completion of a cross-wound bobbin, picks up the thread wound onto the bobbin surface with its suction nozzle, unwinds a certain quantity of thread again from the cross-wound bobbin and temporarily stores it in the suction nozzle. When being wound on again, the thread running from the cross-wound bobbin to the suction nozzle is deflected by guide means on the suction nozzle beyond the end face of the cross-wound bobbin and conveyed in the process into the region of a thread guide element pivotably mounted on the creel.

The thread guide element held by a spring element in the rest position is actuated in the process by the service unit to produce a thread end reserve. In other words, a thread guide contour of the thread guide element is pressed by a control lever arranged on the service unit into the vicinity of the interspace, which is formed by the loose cop and the bobbin tube, and ensures that the thread is wound as a thread end reserve onto the tip of the cross-wound bobbin tube. The thread between the tube and suction nozzle is tautly tensioned here because of the suction flow present in the suction nozzle of the service unit and is wound in relatively firm windings onto the tube.

Similar methods and devices for producing cross-wound bobbins with a thread end reserve are also described in German Patent Publications DE 40 08 001 A1, DE 40 23 291 A1 or DE 40 40 552 C2. A service unit which can be moved along the workstations of the textile machine is also always used in these known devices when producing the thread end reserves of the cross-wound bobbins, which service unit firstly unwinds thread from a cross-wound bobbin before the thread is wound on again in parallel windings.

A bobbin changing carriage, which inter alia has a suction nozzle, a bobbin drive and a spindle-like thread guide mechanism, is described in German Patent Publication DE 40 23 291 A1. To produce a thread end reserve, the suction nozzle is also firstly pivoted into the region of the cross-wound bobbin surface in the case of this bobbin change carriage and the cross-wound bobbin is rotated in the unwinding direction by the bobbin drive. The suction nozzle in this case picks up a certain thread quantity of the thread which has run onto the bobbin surface and stores this thread quantity temporarily. The thread guide configured as a spindle is then pivoted into the thread strand extending between the cross-wound bobbin and suction nozzle and the cross-wound bobbin is rotated in the winding-on direction again, thread being drawn out of the suction nozzle. According to an embodiment, the thread is guided down, in this case, from the bobbin surface, drawn as a chord over the cross-wound bobbin flank and then arranged in parallel windings on the cross-wound bobbin surface.

Furthermore, winding heads of textile machines producing cross-wound bobbins are known from German Patent Publication DE-PS 1 760 243 and are equipped with a mechanism particular to the winding head for producing a thread end reserve. These known winding heads have a thread traversing mechanism with a thread guide which is arranged on a bar along the length of the machine, which bar, like the bobbin drive roller of the winding head, is driven by a group drive arranged in a machine end frame of the textile machine.

A guide strip which is pivotably mounted, provided with a guide notch and extends over the entire bobbin width, is provided in the thread running path upstream of the thread traversing mechanism. This spring force-loaded guided strip is fixed during the winding process by an activatable bolt mechanism in its rest position and is pivoted up when the cross-wound bobbin has reached a predeterminable diameter in such a way that the thread is lifted from the thread guide thread traversing mechanism and is displaced on the guide strip in the direction of the guide notch arranged in the region of a bobbin flank. The thread sliding into the guide notch runs in parallel windings onto the cross-wound bobbin and in the process, before it is severed by an associated thread cutting mechanism, forms a thread end reserve.

A disadvantage in this mechanism is, however, that the thread tension with which the thread is wound on when producing the parallel windings, is substantially reduced compared to the thread tension during the “normal” winding process with the result that the parallel windings are wound relatively loosely. With such loosely wound parallel windings there is then always the risk that the thread end reserves will be detached during the transportation of the cross-wound bobbins from the bobbin bodies.

Furthermore, textile machines producing cross-wound bobbins are known from the generic European Patent Publication EP 1 125 879 A2, the winding heads of which are equipped with various single drives. In other words, these winding heads in each case have a single drive for rotating a cross-wound bobbin and a thread traversing mechanism which can be driven by a single motor. The thread guide of the thread traversing mechanism here can be activated and positioned by a control mechanism in such a way that a thread end reserve which consists of a number of parallel windings, can be selectively placed on the tip of the cross-wound bobbin tube or on the lateral surface of the cross-wound bobbin. The thread end reserves are also wound very loosely in winding heads configured in this manner. In other words, there is also a risk with these known mechanisms that the relatively loosely wound thread end reserves will unintentionally be detached from the bobbin body or the bobbin tube during transportation of the cross-wound bobbins, for example.

SUMMARY OF THE INVENTION

Proceeding from the prior art described above, the invention is based on the object of developing a method or a device which already allows the production of a cross-wound bobbin with a proper, reliable thread end reserve during the winding process, in other words providing a method or a device, in which, during the production of a thread end reserve the unwinding and rewinding of a thread end from a cross-wound bobbin, in particular with the aid of a service unit, can be dispensed with.

This object is addressed according to the invention by a method for operating a winding device of a textile machine producing cross-wound bobbins, which has a creel for the freely rotatable holding of a cross-wound bobbin, a bobbin drive roller, which can be driven by a single drive, for rotating the cross-wound bobbin, and a thread traversing mechanism which can be driven by a single motor and activated in a defined manner. Upon reaching a predeterminable cross-wound bobbin diameter or a predeterminable thread length, the thread guide of the thread traversing mechanism, to produce a thread end reserve for an adjustable time span, is either positioned outside the winding region of the cross-wound bobbin or inside the winding region of the cross-wound bobbin. According to the method of the invention, while the thread end reserve is being produced, a thread storage nozzle particular to the winding head and which can be acted upon with negative pressure is connected and acts on the thread running onto the cross-wound bobbin in such a way that excess thread length being produced during the winding of the thread end reserve is intermediately stored and a minimum thread tension is thereby ensured that is necessary to reliably fix the thread end reserve on the bobbin body or the cross-wound bobbin tube.

Advantageous configurations, features and advantages of the method according to the invention are described in and will be more fully understood from the following disclosure.

The method according to the invention, which is preferably used in winding heads, which have a creel for freely rotatably holding a cross-wound bobbin, a bobbin drive roller which can be driven by a single motor, a thread traversing mechanism which can be driven by a single motor and activated in a defined manner, and a thread storage mechanism particular to the winding head, has the advantage that the thread end reserve can already be implemented by the winding head itself at the end of the “regular” winding process, in other words, there is no need for a wait until a service unit approaches the winding head, unwinds thread from the cross-wound bobbin and winds it on again in parallel windings. It is also ensured by connecting the thread storage nozzle, which can be acted upon with negative pressure and is particular to the winding head, in a simple manner, that the thread is wound at an adequately high thread tension during the production of this thread end reserve since, during the winding of the thread reserve, the thread excess being produced because of the parallel windings is immediately picked up by the thread storage nozzle loaded with negative pressure, as a thread loop, and the thread is thus held taut at all times.

It is provided in an advantageous configuration of the invention that the thread, during the production of the thread end reserve, by means of the thread guide of the thread traversing mechanism, is firstly briefly displaced beyond one of the bobbin flanks of the cross-wound bobbin and immediately displaced back onto the bobbin surface where the thread is then fixed in parallel windings on the bobbin surface of the cross-wound bobbin.

A method of this type achieves, on the one hand, that the thread extends in the form of a thread chord over one of the bobbin flanks and is therefore easy to grip during the further processing of the cross-wound bobbin and, on the other hand, it is ensured that the thread reserve is also fixed adequately firmly on the cross-wound bobbin during the transportation of the cross-wound bobbins.

It has proven to be particularly advantageous if the thread with a cross-wound bobbin diameter of, for example, 350 mm is fixed with three parallel windings on the bobbin surface of the cross-wound bobbin. The thread is adequately securely fixed during the transportation of the cross-wound bobbins on the bobbin surface of the cross-wound bobbin owing to the arrangement of preferably three parallel windings, and can also, if necessary, be easily detached at any time.

The winding device of the textile machine producing cross-wound bobbins, to carry out the method according to the invention, has a creel for freely rotatably holding a cross-wound bobbin, a bobbin drive roller which can be driven by a single drive to rotate the cross-wound bobbin, a thread traversing mechanism which can be driven by a single motor and activated in a defined manner, and a thread storage nozzle which can be connected in a defined manner, the mouth of which is arranged in the region of the running path of the thread. The thread storage nozzle is in turn connected to a negative pressure source and, if necessary, can be loaded with negative pressure, for example, by corresponding activation of a valve. The passing thread is acted upon by the negative pressure present in the region of the mouth of the thread storage nozzle in such a way that excess thread length, such as is inevitably produced on winding heads with a constant thread supply during the production of parallel windings, is immediately sucked into the thread storage nozzle as a thread loop and the thread is thus held taut.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail below with the aid of an embodiment shown in the drawings, in which:

FIG. 1 shows a side view of one half of an open end spinning machine, especially one of the numerous workstations of a textile machine of this type, which are equipped in such a way that the method according to the invention can be carried out,

FIG. 2 shows the workstation shown in FIG. 1 in a perspective view and to a larger scale,

FIG. 3 shows a cross-wound bobbin with a thread end reserve which has been produced by the method according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 indicates one half of an open-end spinning machine known per se and designated 1. Spinning machines of this type have a large number of workstations 2, which are equipped in each case with a spinning device 3 and a winding mechanism 4. The fibre band 6 fed in spinning cans 5 is spun in the spinning devices 3 to form threads 7, which are wound on the winding mechanisms 4 to form cross-wound bobbins 8. As indicated, the winding mechanisms 4 are each equipped with a creel 9 for rotatably holding a cross-wound bobbin 8 or an empty tube, and with a winding drum 11 which can be driven by a single motor to rotate the cross-wound bobbin 8. Furthermore, these substantially self-sufficient workstations 2 described, for example, in German Patent Publication DE 101 39 072 A1, in each case have a thread traversing mechanism 18 driven by a single motor, a thread take-off mechanism 54 driven by a single motor, a suction nozzle 14 particular to the workstation, a piecing member 20 and a thread storage nozzle 60.

In other words, the workstations 2 are equipped in such a way that they can automatically eliminate thread breaks occurring. The open-end spinning machine 1 also has a bobbin transporting mechanism 12 for disposing of the cross-wound bobbins 8 completed on the winding mechanisms 4. A service unit (not shown), for example a so-called changing and clearing carriage, can also be arranged at or on the spinning machine 1 so as to be displaceable on a guide rail 13 and a support rail 15. Service units of this type intervene automatically if a requirement for action occurs at one of the workstations 2. A requirement for action of this type is present, for example, if a full cross-wound bobbin is to be exchanged for a new empty tube at one of the workstations 2.

FIG. 2 shows one of the workstations 2 indicated schematically in FIG. 1 of an open-end rotor spinning machine 1 in a perspective view and to a larger scale. Workstations 2 of this type, as already indicated above with the aid of FIG. 1, inter alia have an open-end spinning device 3 and a winding device 4. Arranged in these self-sufficient workstations 2 known per se, in the region of the so-called thread take-off tube 21 of the open-end spinning device 3 is a piecing member 16, which takes over the thread 7 returned after a thread break by the suction nozzle 14 from the cross-wound bobbin 8 and prepares the thread end for repiecing. Furthermore, such workstations 2 have a thread take-off mechanism 54 which takes over both the drawing off of the spinning thread 7 from the open-end spinning device 3 during the regular spinning operation and also ensures, during the repiecing, a defined return of a prepared thread 7 into the open-end spinning device 3.

The winding mechanism 4 has a creel 9 for rotatably holding the cross-wound bobbin 8, a winding drum 11 which can preferably be driven by a reversible single drive 56, and a thread traversing mechanism 18, which is driven, for example, by means of a stepping motor 57. Furthermore, self-sufficient workstations 1 of this type in each case have a pivotably mounted suction nozzle 14, which can be adjusted in a defined manner by means of a stepping motor 58 between a thread receiving position located in the region of the winding device 4 and a thread transfer position located in the region of the spinning device 3. Each of the workstations 2 also has a stop motion 26, a waxing mechanism 17 and a thread storage nozzle 16 which can be loaded with negative pressure in a defined manner and which is used, on the one hand, during the run up of the workstation 2 to operating speed and, on the other hand, during the production of a thread end reserve 10. In other words, excess thread length is stored by the thread storage nozzle 60 both during the run up of the workstation 2 to operating speed and during the production of a thread end reserve 10 and it is thereby ensured that the thread 7 is always wound on with a specified winding tension.

As can be seen from FIG. 2, both the thread storage nozzle 60 and the pivotably mounted suction nozzle 14 are connected to a negative pressure network 19 particular to the machine, the reduced pressure source of which is designated by the reference numeral 30. The suction nozzle 14 and the thread storage nozzle 60 are connected, for example, via a connection line 22 or 23, in each case, to the negative pressure network 19 of the textile machine 1.

A closure means 24 is integrated here into the connection line 22 and a closure means 25 into the connection line 23, the closure means 24 or 25 being connected via control lines 27, 28 to a control mechanism 29 which is preferably particular to the workstation.

FIG. 3 shows a completed cross-wound bobbin 8, in other words a cross-wound bobbin with a thread end reserve 10, which was produced according to the inventive method. As shown, some parallel windings 32, preferably three, are arranged on the bobbin surface 34. A thread chord 31 is also present in the region of one of the bobbin flanks 35 and can easily be recognised by the operating personnel and can easily be handled to detach the thread end reserve 10.

Functioning of the Method According to the Invention:

During the “normal” spinning/winding operation, the thread 7 produced in the winding device 3 is wound on the winding device 4 to form a cross-wound bobbin 8. In other words, the cross-wound bobbin 8 freely rotatably held in the creel 9 is rotated by the bobbin drum 11 in the winding direction, while the thread 7 running on is simultaneously traversed by the thread traversing mechanism 18. When the cross-wound bobbin 8 has reached a predeterminable diameter, which is detected, for example, by sensors, the thread guide 40 of the thread traversing mechanism 18 is briefly displaced beyond the regular traversing width and immediately guided back into the traversing region, where it is stopped in a predetermined position. The thread 7 is briefly displaced by means of this thread guide movement beyond the bobbin flank 35 and immediately back again onto the bobbin surface 34 in such a way that a thread cord 31 is formed which is then fixed by the parallel windings 32.

During the production of this thread end reserve 10, the closure means 24 is simultaneously actuated to “open” by the control mechanism 29 and the thread storage nozzle 60 is thus connected via the line 22 to the negative pressure network 19 of the textile machine 1. The negative pressure then present at the mouth of the thread storage nozzle 60 acts on the thread 7 running onto the cross-wound bobbin 8 here in such a way that excess thread length being produced is immediately sucked into the thread storage nozzle 60 as a thread loop and the thread is thereby held taut at all times. 

1. Method for operating a winding device of a textile machine producing cross-wound bobbins, which has a creel for the freely rotatable holding of a cross-wound bobbin, a bobbin drive roller, which can be driven by a single drive, for rotating the cross-wound bobbin, and a thread traversing mechanism which can be driven by a single motor and activated in a defined manner, wherein on reaching a predeterminable cross-wound bobbin diameter or a predeterminable thread length, the thread guide of the thread traversing mechanism, to produce a thread end reserve for an adjustable time span, is either positioned outside the winding region of the cross-wound bobbin or inside the winding region of the cross-wound bobbin, characterised in that while the thread end reserve (10) is being produced, a thread storage nozzle (60) particular to the winding head and which can be acted upon with negative pressure is connected and acts on the thread (7) running onto the cross-wound bobbin (8) in such a way that excess thread length being produced during the winding of the thread end reserve (10) is intermediately stored and a minimum thread tension is thereby ensured that is necessary to reliably fix the thread end reserve (10) on the bobbin body or the cross-wound bobbin tube.
 2. Method according to claim 1, characterised in that the thread (7), while the thread reserve (10) is being produced, is firstly displaced beyond one of the bobbin flanks (35, 35A) of the cross-wound bobbin (8) by the thread guide (40) of the thread traversing mechanism (18) and then fixed in parallel windings (32) on the bobbin surface (34) of the cross-wound bobbin (8).
 3. Method according to claim 2, characterised in that the thread guide (40), viewed from the front of the workstation (2), briefly displaces the thread (7) beyond the left bobbin flank (35) of the cross-wound bobbin (8).
 4. Method according to claim 1, characterised in that the thread (7) is fixed by a number of parallel windings (32) depending on the diameter of the cross-wound bobbin (8) on the bobbin surface (34) of the cross-wound bobbin (8).
 5. Winding device of a textile machine producing cross-wound bobbins for carrying out the method according to claim 1, comprising a creel for the freely rotatable holding of a cross-wound bobbin, a bobbin drive roller which can be driven by a single drive for rotating the cross-wound bobbin, and a thread traversing mechanism which can be driven by a single motor and activated in a defined manner, characterised in that each of the numerous workstations (2) of the open end spinning machine (1) is equipped with a thread storage nozzle (60) which can be acted on by negative pressure and can be connected in a defined manner, the mouth of which thread storage nozzle is arranged in the region of the running path of the thread (7) running onto the cross-wound bobbin (8). 